Related papers: Lepton Flavor and Number Conservation, and Physics…
We consider the neutrino sector of a Standard Model with four generations. While the three light neutrinos can obtain their masses from a variety of mechanisms with or without new neutral fermions, fourth-generation neutrinos need at least…
We review the basic mechanisms of neutrino mass generation and the corresponding structure of the lepton mixing matrix. We summarize the status of three-neutrino oscillation parameters as determined from current observations, using…
I discuss charged lepton-flavor violation in physics beyond the standard model and review topics related to it.
The modern theories of Grand Unification (GUT) and supersymmetric (SUSY) extensions of standard model (SM) suppose that the conservation laws of the SM may be violated to some small degree. The nuclei are well-suited as a laboratory to test…
The origin of fermion mass hierarchies and mixings is one of the unresolved and most difficult problem in high-energy physics. One possibility to address the flavour problem is by extending the Standard Model to include a family symmetry.…
Lepton number violation and its relation to neutrino masses is investigated in several versions of the $SU(3)_c\otimes SU(3)_L\otimes U(1)_x$ model. Spontaneous and explicit violation and conservation of the lepton number are considered. In…
Behind the observed pattern of lepton flavor mixing is a partial or approximate mu-tau flavor symmetry --- a milestone on our road to the true origin of neutrino masses and flavor structures. In this review article we first describe the…
Though models with the radiative neutrino mass generation are phenomenologically attractive, the complicated relationship between the flavour structure of additional Yukawa matrices and the neutrino mass matrix sometimes is a barrier to…
In this talk I discuss the connection between neutrino mass, flavour and CP violation. I focus on three neutrino patterns of neutrino masses and mixing angles, and the corresponding Majorana mass matrices. I discuss the see-saw mechanism,…
I introduce a simple phenomenological model of lepton flavor mixing and CP violation based on the flavor democracy of charged leptons and the mass degeneracy of neutrinos. The nearly bi-maximal mixing pattern, which can interpret current…
We study the phenomenology of d=7 1-loop neutrino mass models. All models in this particular class require the existence of several new $SU(2)_L$ multiplets, both scalar and fermionic, and thus predict a rich phenomenology at the LHC. The…
The article reviews the conditions for lepton-flavor conservation in leptonic interactions. The conditions are similar to those developed in the quark sector. For neutrinos the mass eigenstates are unitary superpositions of flavor states…
To explain the small neutrino masses, heavy Majorana neutrinos are introduced in the left-right twin Higgs model. The heavy neutrinos, together with the charged scalars and the heavy gauge bosons, may contribute large mixings between the…
Models involving large extra spatial dimension(s) have interesting predictions on lepton flavor violating processes. We consider some 5D models which are related to neutrino mass generation or address the fermion masses hierarchy problem.…
We study the role of a very general type of flavor symmetry in controlling the strength of R-parity violation in supersymmetric models. We assume that only leptons are charged under a global symmetry whose breaking induces lepton number…
We have revisited the computations of the flavor violating leptonic decays of the $\tau$ and $\mu$ leptons into three lighter charged leptons in the Standard Model with non-vanishing neutrino masses. We were driven by a claimed unnaturally…
The depth of our theoretical understanding of neutrino flavor mixing should match the importance of this phenomenon as a herald of long-awaited empirical challenges to the standard model of particle physics. After reviewing the familiar,…
A tentative approach to explain the flavor puzzle consists of embedding the Standard Model in a larger gauge symmetry that contains a separate gauge group for each fermion family. In such gauge non-universal (or flavor-deconstructed)…
Recent research has indicated that the Standard Model (SM), while historically highly effective, is found to be insufficient due to its prediction of zero mass for neutrinos. With the exception of a few, the majority of the parameters…
We analyse the lepton sector of the Left-Right Twin Higgs Model. This model offers an alternative way to solve the "little hierarchy" problem of the Standard Model. We show that one can achieve an effective see-saw to explain the origin of…